Chesapeake Bay Water Resources: Using Earth Observations to Assess Spatial and Social Disparities in Water Quality Trends Shaping Fishing and Swimming Access in the Chesapeake Bay

The Chesapeake Bay is a source of sustenance, livelihood, and recreation for many in Maryland and surrounding areas. Harmful algal blooms and hypoxic conditions in the bay threaten these estuarine communities that rely on them. With support from our partners, Ocean Conservancy and Blacks of the Chesapeake Foundation, we investigated chlorophyll-a and turbidity trends in Anne Arundel and Dorchester Counties and focused specifically on how social vulnerability and water quality at recreational public access sites relate to one another to support outreach and public advocacy initiatives. This project utilized Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and Sentinel-3 Ocean and Land Colour Instrument (OLCI) imagery to analyze water quality trends and identify areas with high social vulnerability. While we were not able to tease out larger trends in chlorophyll-a persistence across the entire Chesapeake Bay, we did identify certain recreational access sites in our study area that experienced sustained chlorophyll-a levels surpassing the Maryland Department of Natural Resources’ threshold for significant harmful algal blooms. We also found no significant difference between the linear distance to recreation sites at low, medium, and high socially vulnerable groups; however, we did identify block groups experiencing high social vulnerability and low proximity to recreation sites. In most cases, we found that in situ monitoring sites were not within an acceptable distance to assess chlorophyll-a and turbidity values and validate satellite data at every recreation site. Despite these limitations, this project demonstrated some feasibility in using Earth observations to assess chlorophyll-a and turbidity levels in Chesapeake Bay.